The invention is directed to a drive circuit for a power MOSFET with a load at the source side having first and second diodes connected following one another, at whose junction a first terminal of the capacitor is connected. An oscillating voltage is applied to the second terminal of this capacitor. The second diode is connected to a gate terminal of the power MOSFET. The first diode connects to a voltage source.
Such a drive circuit, for example, has been disclosed by European Patent 0 236 967, corresponding to U.S. Pat. No. 4,737,667. In an integrated arrangement of this type, the diodes cannot be manufactured in a self-insulating technique because of parasitic transistor effects when inhibiting or blocking voltages higher than 0.5 . . . 0.7 V must be provided. The conducting voltage of 0.5 . . . 0.7 V inherent in the diodes, moreover, leads to losses that can no longer be left out of consideration when the operating voltage amounts, for example, to only 5 V.